Here is the full list of all 50 Wolfenstein: The New Order achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Collect all letters
Unlock stealth perk 4
Unlock tactical perk 7
Unlock demolition perk 7
Unlock demolition perk 6
Unlock stealth perk 6
Unlock demolition perk 4
Solve the first Enigma code
Unlock tactical perk 6
Unlock stealth perk 3
Unlock tactical perk 5
Unlock demolition perk 8
Choose to save Wyatt
Unlock assault perk 4
Unlock demolition perk 3
Unlock demolition perk 2
Complete game on any difficulty
Release friend
Unlock assault perk 3
Defeat the London Monitor
Unlock assault perk 6
Unlock tactical perk 4
Unlock tactical perk 8
Collect 25 gold items
Unlock assault perk 8
Locate the underwater stash
Unlock stealth perk 8
Find the Laserkraftwerk
Unlock tactical perk 3
Unlock demolition perk 1
Unlock assault perk 2
Locate the resistance
Unlock stealth perk 7
Unlock stealth perk 5
Unlock tactical perk 2
Unlock stealth perk 2
Choose to save Fergus
Unlock stealth perk 1
Unlock tactical perk 1
Unlock assault perk 1
Save allied planes
Complete game on I AM DEATH INCARNATE! (or ÜBER)
Complete game on ÜBER
Collect all gold items
Solve the second Enigma code
Solve the third Enigma code
Solve the fourth Enigma code
Unlock assault perk 5
Unlock assault perk 7
Unlock demolition perk 5